We have a whitefly problem. We have sprayed three times with an oily liquid suggested by a local gardening shop. It is not working. They are on the hibiscus and pentas.

R.B., Dallas

I have had good results using the garlic-pepper tea formula. Another home remedy is the addition of 1 tablespoon of Lemon Joy dishwashing liquid to a gallon of water. The commercial product Bio Wash also is effective.

My wife has allowed our dog to urinate in a flower bed where I planted English ivy. The ivy is now dying. Is there anything I can do to neutralize the soil?

J.L., Dallas

There are two choices. Apply dry zeolite to the ground in the problem areas to absorb the ammonia and the related odor. Spraying the Garrett Juice mix with 1 ounce of orange oil per gallon of spray will help detox the plants as well as the soil. You can mix your own batch of Garrett Juice, rather than purchasing the ready-to-use concentrate, by following the free recipe on dirtdoctor.com.

Are braconid wasps the same as trichogramma wasps? Will they help control or eliminate flea beetles on my tomatoes?

P.B., Dallas

Braconid wasps are visible to the naked eye, and trichogrammas are microscopic. Both control caterpillars. The trichogrammas kill the eggs by parasitizing them, and the braconids kill the larvae by laying eggs that pupate on the backs of the caterpillars. Both are extremely beneficial insects.

Tiny ants that are light brown with a lighter bottom are eating the new growth on a 60-year-old rosebush that has been transplanted.

A.S., Castrovillle

Spraying Bio Wash on the rose will take care of them. Garlic-pepper tea would also be effective.

My neighbor sprayed an unknown weed killer and now my bed of bearded irises is dying. What can be done to save them?

D.K., Frisco

Applying a fine-textured humate or activated charcoal will tie up any of the remaining toxin. Mixing humate in water and spraying the iris bed would be more effective than a dry application. Applying zeolite to the beds at 10 pounds per 100 square feet also would help.

Can I use leftover coffee from the coffeepot for compost tea? Or do I need to use the coffee grounds?

D.R., Fort Worth

That will work fine.

Resources

Online: Find the free recipes to make your own Garrett Juice and garlic-pepper tea and other gardening information at dirtdoctor.com.